Metal or alloy nanoparticles are generally prepared by chemically reducing metal salt precursors. However, the existing method for preparing catalysts by chemical synthesis is disadvantageous in that the expensive metal salt precursors are necessary and particular solvents have to be used depending on the precursors.
Fuel cell catalysts supported on carbon are advantageous in that they can enhance the flow of electrons generated by electrochemical reactions and ensure discharge of water generated by electrochemical reactions, aggregation of the catalysts can be prevented because of the large surface area of the catalysts, transport of fuel gas such as hydrogen or oxygen can be improved, and the triple phase boundary (between the catalyst, Nafion and carbon) can be greatly increased.
For these reasons, many researchers have made efforts to support the highly dispersible nanosized catalyst (platinum) on carbon through chemical reduction. However, it requires many (5 or more) steps and the catalyst precursor costs about 100 times as compared to the sputtered Pt atoms. Accordingly, there is a need for development of a method that allows supporting of very uniform catalyst particles on carbon with a small number of steps and at low cost.